Semiconductor Integrated Circuits (ICs) are generally fabricated in wafer form or in package form. After the fabrication process, each wafer or package is typically singulated into multiple components. The components can include semiconductor dies or plastic packages such as quad flat no lead (QFN), Chip Scale (CSP), or ball grid array (BGA) packages. The semiconductor components typically undergo numerous processing steps including inspection, testing, and handling processes before they are ready to be packaged and distributed from a semiconductor fabrication facility to other destinations, e.g., for subsequent sale.
Each processing step generally occurs at a distinct or different processing station or module. Typically, the semiconductor component is first retrieved by a component handling device at or from a first or current station, and transferred and thereafter deposited or detached at a second or next station. Semiconductor components are processed at the processing stations either while in motion or while temporarily stationary at the processing stations, depending on processing requirements. The manner in which components are retrieved, handled, and deposited from one processing station to another plays a critical role in ensuring that the components are not damaged, more so when semiconductor component handling operations are automated in a compact space and in a high speed environment.
Existing component handling devices for transferring semiconductor components can include, for example, a robotic assembly or rotatable assembly or any other pick-and-place system well known in the art. Various types of component handling devices have multiple component pickup head assemblies or mechanisms, which can also be referred to as component pickup heads or component handlers for retrieving, receiving, holding, and transferring components. Generally, semiconductor components that have been retrieved or received and are held by the pickup head(s) are transferred between and positioned at different processing stations by way of the pickup head(s) as displacement of the pickup head(s) occurs along a predetermined travel profile or path.
Typically, a pickup head must be precisely or very precisely positioned over a pickup surface (e.g., a component top surface, bottom surface, or side surface) of each component requiring transfer on a repeated, successive, or ongoing basis in order to ensure that component pickup operations occur in a consistent, predictable, and error-free manner. Moreover, the force that the pickup head exerts on the components retrieved thereby must be (a) sufficiently large to ensure that components are securely and reliably held or retained by the pickup head and (b) sufficiently small to minimize the likelihood of component damage. Minimizing the likelihood of component damage can be particularly important in component pickup situations involving fragile components (e.g., thin or very thin semiconductor die), especially when the economic cost or value of each fragile component at the manufacturing stage during which component pickup occurs is non-trivial or significant (e.g., after multiple or many complex component fabrication processes or steps have already been performed).
A component pickup head is commonly used in association with or includes a soft or deformable tip element, which can be a replaceable element that is attached to a predetermined end of the component pickup head at which components are retrieved, and which comes into contact with each component as part of the component retrieval or pickup process. Tip elements can deteriorate or degrade over time as a result of successive component pickup operations, and thus the length or height of a tip element can become smaller over time. Consequently, the precision and reliability of component pickup operations can deteriorate or degrade over time because the vertical distance between the distal end of the tip element and component pickup surfaces can increase over time, possibly in a non-uniform or less than readily predictable manner.
In some types of component pickup situations, for instance, when semiconductor die reside on or are adhered to a deformable (e.g., vertically deformable) surface such as a conventional tape carried by a film frame, the pickup head is configured such that the tip element engages with and intentionally slightly presses against the pickup surface of each component while the component resides on the tape, to thereby exert an intended amount of downward compressive force on the component pickup surface in order to provide an adequate grip for consistently overcoming the adhesive force holding the component on the tape and picking up or removing components from the tape. In such situations, the component can be damaged if there is excessive force exerted on the component pickup surface when the pickup head is pressed thereon or thereagainst. This compressive force can be established in accordance with a predetermined target compressive force level depending on the type and thickness of semiconductor components under consideration. However, in conventional component handling systems, apparatuses, and devices, precise calibration, measurement, adjustment, and monitoring of compressive forces applied to components are difficult to achieve and practically infeasible, particularly due to the small, compact nature of the pickup heads and the highly confined spaces in which the component handling devices operate.
In view of the foregoing, in order to properly and consistently retrieve the semiconductor components in a safe or damage-free manner, the position and vertical travel of the pickup head(s) need to be precisely calibrated prior to the initiation of regular, sustained, ongoing, or post-calibration component pickup operations. This calibration is typically performed manually by a technician. However, the manual process pickup head calibration process involves a significant amount of time, adversely affecting throughput; as well as a great deal of trial and error, which is prone to human error and which leads to insufficiently reliable or inconsistent component pickup, and/or inadequate or excessive compressive force applied to the semiconductor components during the post-calibration component retrieval operations. In addition, there are no existing devices or mechanisms for determining or monitoring the compressive force(s) exerted on components during component handling device operation.
Accordingly, in order to address or alleviate the aforementioned problems and/or disadvantages associated with conventional component handling devices, there is a need for a system, apparatus, device, and process for automatically setting an intended compression threshold to prevent the pickup head(s) from inadequately or excessively pressing onto the semiconductor components during component retrieval operations and/or automatically precisely calibrating the travel (e.g., vertical travel) of component pickup head(s) to component pickup surfaces, and which can facilitate or enable monitoring or measurement of pickup head performance and component pickup consistency over time.